Influence of Matrix Molecular Weight on a Brush - Like Surface Layer Formed by a Polymer Functionalised at Both Ends

1997 ◽  
Vol 7 (12) ◽  
pp. 1871-1891 ◽  
Author(s):  
F. T. Kiff ◽  
R. W. Richards ◽  
H. L. Thompson ◽  
D. G. Bucknall ◽  
J. R.P. Webster
Keyword(s):  
Molecular Weight ◽  
Surface Layer

A new calculation of the kinetics of the renneting reaction

1988 ◽  
Vol 55 (4) ◽  
pp. 521-528 ◽  
Author(s):  
Douglas G. Dalgleish
Keyword(s):  
Molecular Weight ◽  
Surface Layer ◽  
Analytical Solution ◽  
Enzyme Concentration ◽  
Detailed Calculation ◽  
Repulsive Potential ◽  
First Order ◽  
Coagulation Process ◽  
Kinetics Of

SummaryA detailed calculation of the growth of molecular weight during the renneting of milk is given, based on a first-order breakdown of κ-casein followed by development of instability caused either by a decrease in the intermicellar repulsive potential or by the formation of holes in the stabilizing surface layer of the micelles. Unlike most of the models which have been described, this model allows a complete analytical solution. The solution is, however, complex and difficult to use simply, although it is shown that the calculations are in accord with experimental observations of the dependence of the coagulation process upon the enzyme concentration and the concentration of the milk. The calculations are also compared with those from other models of the reaction.

Tribotechnical properties of ultra-high molecular weight polyethylene filled with sulfur, diphenylguanidine and 2-mercaptobenzothiazole

2020 ◽  
pp. 91-98
Author(s):  
S. N. Danilova ◽  
A. A. Dyakonov ◽  
A. P. Vasiliev ◽  
Y. S. Gerasimova ◽  
A. A. Okhlopkova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Wear Resistance ◽  
Surface Layer ◽  
Ir Spectroscopy ◽  
High Molecular Weight ◽  
High Wear Resistance ◽  
Carbonyl Groups ◽  
Tribotechnical Properties ◽  
Ultra High Molecular Weight

The paper studies tribotechnical properties, hardness and density of composites based on ultra-high molecular weight polyethylene (UHMWPE) filled with sulfur, diphenylguanidine (DFG) and 2-mercaptobenzothiazole (MBT) and their mixtures. It has been established that the introduction of selected fillers has practically no effect on hardness and density of the composites, but leads to a significant (by 2–3 times) increase in the wear resistance of materials. Using electron microscopy, it has been established that secondary structures are formed in composites containing MBT that protect the surface layer of the material from wear. Using IR spectroscopy, it was established that tribochemical reactions occur during the wear of composites with the formation of hydroxyl and carbonyl groups. The developed materials UHMWPE / MBT and UHMWPE / FGD / MBT have high wear resistance and can be used as materials for tribological purposes.

Effects of Ultrapure Hemodialysis and Low Molecular Weight Heparin on the Endothelial Surface Layer

2014 ◽  
Vol 38 (3-4) ◽  
pp. 203-210 ◽  
Author(s):  
Tom Cornelis ◽  
Natascha J.H. Broers ◽  
Denise C.L.M. Titulaer ◽  
Yvonne M. Henskens ◽  
Rene van Oerle ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Surface Layer ◽  
Low Molecular Weight Heparin ◽  
Low Molecular Weight ◽  
Endothelial Surface Layer ◽  
Endothelial Surface

Evaluation of the dark field method for large association of spread DNA

1978 ◽  
Vol 36 (2) ◽  
pp. 190-191
Author(s):  
Douglas C. Barker
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Mitochondrial Dna ◽  
Extraction Method ◽  
Field Method ◽  
Dark Field ◽  
Kinetoplast Dna ◽  
Field Electron ◽  
Field Electron Microscopy ◽  
Dark Field Electron

A number of satisfactory methods are available for the electron microscopy of nicleic acids. These methods concentrated on fragments of nuclear, viral and mitochondrial DNA less than 50 megadaltons, on denaturation and heteroduplex mapping (Davies et al 1971) or on the interaction between proteins and DNA (Brack and Delain 1975). Less attention has been paid to the experimental criteria necessary for spreading and visualisation by dark field electron microscopy of large intact issociations of DNA. This communication will report on those criteria in relation to the ultrastructure of the (approx. 1 x 10-14g) DNA component of the kinetoplast from Trypanosomes. An extraction method has been developed to eliminate native endonucleases and nuclear contamination and to isolate the kinetoplast DNA (KDNA) as a compact network of high molecular weight. In collaboration with Dr. Ch. Brack (Basel [nstitute of Immunology), we studied the conditions necessary to prepare this KDNA Tor dark field electron microscopy using the microdrop spreading technique.

Introduction

1978 ◽  
Vol 36 (3) ◽  
pp. 543-544
Author(s):  
W. Bernard
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Nucleic Acid ◽  
Gene Mapping ◽  
Molecular Genetics ◽  
Cell Biology ◽  
Gene Activity ◽  
Close Connection ◽  
Basic Information ◽  
Simple Systems

In comparison to many other fields of ultrastructural research in Cell Biology, the successful exploration of genes and gene activity with the electron microscope in higher organisms is a late conquest. Nucleic acid molecules of Prokaryotes could be successfully visualized already since the early sixties, thanks to the Kleinschmidt spreading technique - and much basic information was obtained concerning the shape, length, molecular weight of viral, mitochondrial and chloroplast nucleic acid. Later, additonal methods revealed denaturation profiles, distinction between single and double strandedness and the use of heteroduplexes-led to gene mapping of relatively simple systems carried out in close connection with other methods of molecular genetics.

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